Hi Dockside
Have you found an answer yet? Typically the tender numbers are ink stamped in silver on the bottom of the chassis. I do recall 2 postwar tenders with 6 wheel trucks. After searching I cam up with the #2426W which went with the #726 and #723 engines. and the #2671W Pennsylvania Tender possibly paired up with the #671 and #681 engines. Not sure of any more or any newer versions